SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY: A NOVEL AND FAST TOOL FOR NDT

Spectral-domain Optical Coherence Tomography (SD-OCT) is a new, promising variant of OCT, providing superior sensitivity and measurement speed for cross-sectional imaging of turbid materials. OCT, originally developed for applications in the field of biomedical diagnostics, has shown high potential for other non-biomedical investigation tasks, e.g. within the field of non-destructive testing (NDT) and contactless material characterization. However, mostly standard OCT techniques have been used for these applications. Therefore, we demonstrate and evaluate, partly for the first time, the suitability of SD-OCT for selected applications in the field of NDT: contactless imaging of the interior of materials for the determination of the thickness of polymer layers and for the detection of defects in fibre reinforced polymer composites as well as the evaluation of their surface structure is demonstrated. Finally, we investigate the effect of the measurement wavelength on the achievable penetration depth by imaging polymer foam samples with different pore geometries.